【摘要】 研究香蕉miRNA在冷胁迫处理下的动态表达,初步探索miRNA在香蕉冷胁迫过程中的可能作用。利用茎环引物实时荧光RT-PCR(stem-loop qRT-PCR)策略,检测冷胁迫响应miRNA在5℃冷胁迫处理不同时间点香蕉幼苗叶片中的表达模式。结果表明,在检测的15个香蕉miRNAs中,不同的miRNA在同一冷胁迫时间下的表达量存在很大差异。根据其表达模式,可将15个miRNA分成4组。组1和组2中的12个miRNA(miR159e、miR159f、miR160-3p、miR397a、miR399j、miR164e、miR444a、miR408、miR5179、miR530、miR535和miR5538),在5℃冷胁迫处理下表达量总体为上调,其在胁迫过程中的平均表达水平高于对照CK(0 h),说明冷胁迫诱导此类miRNA的表达。第3组包括miR156l、miR162a和miR166a,其在5℃冷胁迫处理各时间点的表达量均低于对照,为下调表达,说明冷胁迫抑制此类miRNA的表达。第4组仅含1个miRNA,即miR156a,除在冷胁迫处理12 h表达量明显上调外,其余时间点均下调表达。对这些miRNAs作用的靶基因进行预测和分析发现,它们主要参与植物的新陈代谢、信号传导和生长发育过程等。这为进一步验证与低温胁迫相关的目的miRNA的功能提供理论依据。更多还原

【Abstract】 To explore the potential roles of miRNA in banana under cold stress, we analyzed the dynamic expression of cold responsive miRNAs in banana. The expression profiling of cold-responsive miRNAs in banana leaves was detected by stem-loop qRT-PCR after 0, 2, 4, 8, 12 and 24 h of cold stress at 5℃. The results showed that fifteen potential cold-responsive miRNA were expressed and exhibited different expression patterns at different treatment stages. The 15 miRNA were divided into 4 groups according to their expression pattern. Generally, the expressions of Group I(miR159 e, miR159 f, miR160-3 p, miR397 a, miR399 j, miR408,miR5179, miR530, miR535 and miR5538) and II(miR164 e and miR444 a) were up-regulated at 5℃ cold stress. During the cold stress, the average expression level of these miRNA was higher than the control(0 h).miR156 l, miR162 a and miR166 a were in Group III, and their expression was reduced during the whole period of the cold treatment. Group IV had only one miRNA(miR156 a), its expression was significantly increased only at 12 h and reduced at the rest of the time points under cold stress. The analysis of the target genes of these miRNA revealed that these miRNA participated in the signal transduction, growth and development and stress response under abiotic stress. These findings provide valuable information for further functional characterization of miRNA associated with cold stress in banana.更多还原